摘要
【目的】以基于茶多酚的思茅松树皮多聚原花青素降解反应中(-)-表儿茶素-(4β-8)-(-)-表没食子儿茶素3-O-没食子酸酯(化合物1)的含量作为评价指标,确定思茅松树皮多聚原花青素的最佳降解条件,为思茅松树皮多聚原花青素降解产物的进一步开发利用提供基础。【方法】采用HPLC定量分析方法测定各反应溶液中化合物1的含量,通过单因素试验考察反应温度(50~90℃)、反应时间(30~180 min)、盐酸浓度(0.1%~5%)和茶多酚/多聚原花青素比率(1∶3~3∶1,w/w)对化合物1生成的影响。采用4因素5水平中心组合旋转设计的响应面法优化其降解条件,以化合物1的含量为响应值,以上述4个因素为自变量,利用Design-Expert V8.0.6软件对28个试验点测定所得数据进行多元非线性分析,建立回归模型,并通过方差分析对模型进行显著性检测。【结果】反应温度、盐酸浓度和茶多酚/多聚原花青素比率明显影响降解反应中化合物1的生成,建立的回归模型极显著(P<0.000 1),且线性系数良好(R2=0.952 6),说明建立的数学模型能较好地描述试验结果,可用于分析和预测化合物1的生成。思茅松树皮多聚原花青素的最佳降解条件为反应温度70℃、反应时间60 min、盐酸浓度1%和茶多酚/多聚原花青素比率3∶2。经验证此条件下反应液中化合物1的浓度可达718.57 nmol·mL^(-1),与理论值(721.39 nmol·mL^(-1))较为接近。【结论】采用中心组合旋转设计的响应面法分析优化思茅松树皮多聚原花青素降解以获取主产物(-)-表儿茶素-(4β-8)-(-)-表没食子儿茶素3-O-没食子酸酯的方法可行。
【Objective 】（-）-epicatechin-（4 β-8）-（-）-epigallocatechin 3-O-gallate（1） was found to be the main depolymerized product of polymeric proanthocyanidins（PPC） from the pine barks with tea polyphenols（TP）,and showed higher DPPH and ABTS＋radical scavenging activities than both PPC and TP. In order to provide the basis for further development and utilization of depolymerized product of PPC,the objective of this study was to optimize the depolymerization process of PPC from the barks of Pinus kesiya var. langbianensis with TP,by using the content of 1 as an evaluation indicator. 【Method】The content of compound 1 in reacted solution was analyzed by HPLC,and the effects of reaction temperature（50-90 ℃）,reaction time（30-180 min）,HCl concentration（0. 1 %-5 %） and TP/PPC ratio（1 ∶ 3-3 ∶ 1,w/w） on the content of 1 were investigated by single factor experiments. The depolymerizationprocess was optimized using response surface methodology,at a five-level,four-variable experiment central composite rotatable design. Using the content of 1 as response,and above four factors as variables,the twenty-eight experiments were conducted to analyze the response pattern and to establish model for reaction process. The responses obtained from the experimental design set were subjected to multiple nonlinear regression using Design-Expert V8. 0. 6 software to obtain the coefficients of the second-polynomial model, and its statistical significance was evaluated by variance analysis. 【Result】The reaction temperature,HCl concentration and TP/PPC ratio strongly affects the content of 1 in the depolymerization reaction. The regression model was very significant（P 0. 000 1） with a good coefficient（R2=0. 952 6）,suggesting that the proposed experimental design was suitable to analysis and to predict the simulation of 1.The optimum depolymerization conditions were as follows： reaction temperature 70 ℃,reaction time 60 min,HCl concentration 1 %,and TP/PPC ratio 3 ∶ 2. Under the above-mentioned conditions,the experimental content of 1 was718. 57 nmol·mL-1,which was well matched with the predicted content（721. 39 nmol·mL-1）. 【Conclusion】It was feasible to use response surface method to optimize the depolymerization process of PPC from the barks of P. kesiya var.langbianensis with TP for the production of 1.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2017年第2期110-116,共7页
Scientia Silvae Sinicae
基金
National Natural Science Foundation of China(31260163)
Yunnan Provinical Department of Education Research Fund(ZD2010006)
